As aforementioned, the present invention relates to a new and novel construction for what may be termed a coupler device for centering and detachably locking a floor maintenance pad to what it termed a pad holder. The pad holder is, in turn, detachably connected to the drive shaft of a power-driven floor maintenance machine of the type described in applicant's aforementioned U.S. Pat. No. 4,114,225. Such floor maintenance pads are generally of a circular configuration and made from a deformable and flexible material such as of a mesh or woven construction made from synthetic or natural fibers, steel wool or the like. Such pads are conventionally known in the art and have a predetermined density or porosity so as to provide the desired cleaning, stripping, polishing, scrubbing or other such floor maintenance application.
Heretofore, and as recognized in applicant's prior patent, there is a need to be able to maintain such pads in centered relation relative to the vertical axis of the drive shaft of the machine power source and to lock the pad in such centered relationship during relatively high speed operations especially in those situations where the machine is "heeled" back away from the surface to be treated such as when moving over or around an object (i.e. door threshold, corners, etc.) or when replacing the pad. Accordingly, continuing efforts have been made to improve the nature and quality of the centering and/or locking features of the coupler device while providing quick and easy installation and removal of the pad and without damage to the surface to be treated during use therof.